Chris, you have listed alot of interesting and helpful information here and I thank you for that. What kind of formula do you use to get this information. I have 3.55's with 33's and while I didn't see any noticeable difference in driveability, according to your input if I switched to 3.73 it would therotically increase my mileage around town without hurting highway mileage.
I am also considering purchase of a travel trailer down the road and may need to change gears or downsize tires to handle to load based on what has been written here.

Thanks, Gerald